Regulation (EU) No 1007/2011 of the European Parliament and of the CouncilShow full title

METHOD No 3 U.K. [F1 VISCOSE, CUPRO OR CERTAIN TYPES OF MODAL AND CERTAIN OTHER FIBRES U.K. (Method using formic acid and zinc chloride)] U.K.

1. FIELD OF APPLICATION U.K.

This method is applicable, after removal of non-fibrous matter, to binary fibre mixtures of:

1.

viscose (25) or cupro (21), including certain types of modal fibre (22)

with

2.

[F1 cotton (5), polypropylene (37), elastolefin (46) and melamine (47).

If a modal fibre is found to be present, a preliminary test shall be carried out to see whether it is soluble in the reagent.

This method is not applicable to mixtures in which the cotton has suffered extensive chemical degradation nor when the viscose or cupro is rendered incompletely soluble by the presence of certain dyes or finishes that cannot be removed completely.]

2. PRINCIPLE U.K.

The viscose, cupro or modal fibre is dissolved from a known dry mass of the mixture, with a reagent consisting of formic acid and zinc chloride. The residue is collected, washed, dried and weighed; its corrected mass is expressed as a percentage of the dry mass of the mixture. The percentage of dry viscose, cupro or modal fibre is found by difference.

3. APPARATUS AND REAGENTS (other than those specified in the general instructions) U.K.

3.1. Apparatus U.K.

(a) Glass-stoppered conical flasks of at least 200 ml capacity. U.K.

(b) Apparatus for maintaining flasks at 40 ± 2 °C. U.K.

3.2. Reagents U.K.

(a) Solution containing 20 g of fused anhydrous zinc chloride and 68 g of anhydrous formic acid made up to 100 g with water (namely 20 parts by mass of fused anhydrous zinc chloride to 80 parts by mass of 85 % m/m formic acid). U.K.

Note: U.K.

Attention is drawn, in this respect, to point I.3.2.2, which lays down that all reagents used shall be chemically pure; in addition, it is essential to use only fused anhydrous zinc chloride.

(b) Ammonium hydroxide solution: dilute 20 ml of a concentrated ammonia solution (relative density at 20 °C: 0,880) to 1 litre with water. U.K.

4. TEST PROCEDURE U.K.

Follow the procedure described in the general instructions and proceed as follows: place the specimen immediately in the flask, pre-heated to 40 °C. Add 100 ml of the solution of formic acid and zinc chloride, pre-heated to 40 °C per gram of specimen. Insert the stopper and shake the flask vigorously. Keep the flask and its contents at a constant temperature of 40 °C for 2,5 hours, shaking the flask at hourly intervals.

Filter the contents of the flask through the weighed filter crucible and with the help of the reagent transfer to the crucible any fibres remaining in the flask. Rinse with 20 ml of reagent pre-heated to 40 °C.

Wash crucible and residue thoroughly with water at 40 °C. Rinse the fibrous residue in approximately 100 ml of cold ammonia solution (3.2(b)) ensuring that this residue remains wholly immersed in the solution for 10 minutes(1); then rinse thoroughly with cold water.

Do not apply suction until each washing liquor has drained under gravity.

Finally, drain the remaining liquid with suction, dry the crucible and residue, and cool and weigh them.

[F1 5. CALCULATION AND EXPRESSION OF RESULTS U.K.

Calculate the results as described in the general instructions. The value of ‘ d ’ is 1,00, except for cotton, for which ‘ d ’ = 1,02 and for melamine, for which ‘ d ’ = 1,01.]

6. PRECISION U.K.

On a homogeneous mixture of textile materials, the confidence limits of results obtained by this method are not greater than ± 2 for a confidence level of 95 %.

Textual Amendments

F1 Substituted by Commission Delegated Regulation (EU) No 286/2012 of 27 January 2012 amending, in order to include a new textile fibre name, Annex I, and, for the purposes of their adaptation to technical progress, Annexes VIII and IX to Regulation (EU) No 1007/2011 of the European Parliament and of the Council on textile fibre names and related labelling and marking of the fibre composition of textile products (Text with EEA relevance).

(1)

To ensure that the fibrous residue is immersed in the ammonia solution for 10 minutes, one may, for example, use a filter crucible adaptor fitted with a tap by which the flow of the ammonia solution can be regulated.